package main

import "fmt"

type Person interface {
	Speaking(str string) string
}
type Student struct {
}

func (stu Student) Speaking(str string) string {
	if str == "a" {
		return "大哥"
	} else {
		return "小弟"
	}
}

func main() {
	var peo Person = &Student{}
	str := "sas"
	fmt.Println(peo.Speaking(str))
}
